Maciejewski #1 Reservoir Report
Nearby: Henry Holwenger Mcgee Dam
Last Updated: December 13, 2025
Maciejewski #1 is a privately owned earth dam located in Corson, South Dakota, along the TR MOREAU river.
°F
°F
mph
Wind
%
Humidity
Summary
Built in 1944, this dam stands at 18 feet high and spans a length of 600 feet, with a storage capacity of 55 acre-feet. It is regulated by the South Dakota Department of Environment and Natural Resources (DENR) and is subject to state permitting, inspection, and enforcement.
Despite being classified as a low hazard potential structure, Maciejewski #1 has not been rated for its condition assessment. The dam has not undergone recent inspections, and there is no emergency action plan (EAP) in place. With no designated risk assessment or management measures, the structure's safety and maintenance protocols remain uncertain.
With its location in a region susceptible to climate variability and water resource challenges, enthusiasts of water management and climate resilience may find Maciejewski #1 to be a case study worth monitoring. As a privately owned dam with state oversight, the lack of recent assessments and emergency preparedness highlights the importance of proactive monitoring and risk management for such critical infrastructure in the face of evolving climate conditions.
Year Completed |
1944 |
Dam Length |
600 |
Dam Height |
18 |
River Or Stream |
TR MOREAU |
Primary Dam Type |
Earth |
Hydraulic Height |
18 |
Nid Storage |
55 |
Hazard Potential |
Low |
Nid Height |
18 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Cedar Creek Nr Raleigh
|
20cfs |
Grand R At Little Eagle Sd
|
47cfs |
Cannonball River Nr Raleigh
|
40cfs |
Oak Cr Near Wakpala Sd
|
10cfs |
Cannonball River At Breien
|
96cfs |
Moreau R Near Whitehorse Sd
|
35cfs |
Dam Data Reference
Condition Assessment
SatisfactoryNo existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
Fair
No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
Poor A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency. Investigations and studies are necessary.
Unsatisfactory
A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
Not Rated
The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Not Available
Dams for which the condition assessment is restricted to approved government users.
Hazard Potential Classification
HighDams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
Significant
Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environment damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
Low
Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
Undetermined
Dams for which a downstream hazard potential has not been designated or is not provided.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.
Maciejewski #1